The location of the signs must be visible and unobstructed to motorists and pedestrians for them to effectively communicate information. Horizontal and vertical sight distances must be checked to ensure that the sign is unobstructed and that motorists and pedestrians have adequate time to react to what the sign is communicating.

Large sign structures are a roadside obstacle that require appropriate safety treatment. Large sign structures deemed crashworthy by the Department may be placed within the clear zone without additional safety treatment; otherwise, the appropriate clear zone requirements must be checked to ensure that the proper safety treatment is used.

Large sign structure locations should be reviewed to ensure they do not adversely impact hydraulic operation of roadside ditches.

If this cannot be avoided proper scour countermeasures shall be designed and installed to protect the ditch and sign foundation integrity.

Existing utilities and subsurface features such as culverts, storm sewer, waterlines, and gas lines can also influence the location of sign structures. Foundations must be verified with subsurface data to ensure clearance requirements are met.

Enhanced signing may increase safety of highway facilities in targeted areas with a high frequency of crashes or constrained geometry such as horizontal and/or vertical curves with limited sight distance. Where bicycles and pedestrians are present, enhanced signing should be used to alert drivers to pedestrian crossings and on-road bicycle facilities.